What are the intramuscular (IM) doses of Haloperidol (antipsychotic medication)?

From the Guidelines

Haloperidol IM dosing should start at 5-10 mg for adults, which can be repeated every 20-30 minutes if needed, with a maximum daily dose of 40 mg. For adolescents, the dose can range from 0.5-1 mg to 5-10 mg, depending on the age and weight of the patient, with a maximum daily dose of 30 mg 1. When administering haloperidol IM, it is essential to monitor for extrapyramidal symptoms, QT prolongation, and sedation. Some key points to consider when using haloperidol IM include:

• The dose can be repeated every 20-30 minutes if needed, with a maximum daily dose of 40 mg for adults and 30 mg for adolescents 1.
• The use of haloperidol IM in combination with other medications, such as lorazepam or midazolam, may be necessary for older adolescents 1.
• The dose for children can range from 0.25-0.50 mg to 2.5 mg, depending on the age and weight of the patient 1.
• It is crucial to assess the patient's response after each dose and be prepared to manage potential adverse effects. Consider starting with the lowest effective dose and titrating up as needed to minimize side effects, and concurrent use of anticholinergic medications like benztropine may be necessary to manage extrapyramidal symptoms 1.

From the FDA Drug Label

DOSAGE AND ADMINISTRATION Haloperidol decanoate injection, 50 mg (base)/mL and haloperidol decanoate injection, 100 mg (base)/mL should be administered by deep intramuscular injection. The initial dose of haloperidol decanoate, USP should not exceed 100 mg regardless of previous antipsychotic dose requirements. The maintenance dosage of haloperidol decanoate, USP must be individualized with titration upward or downward based on therapeutic response. The usual maintenance range is 10 to 15 times the previous daily dose in oral haloperidol equivalents dependent on the clinical response of the patient

The recommended IM doses of Haloperidol are:

• Initial dose: 10-20 times the previous daily dose in oral haloperidol equivalents, not to exceed 100 mg
• Maintenance dose: 10-15 times the previous daily dose in oral haloperidol equivalents, individualized based on therapeutic response 2

From the Research

Haloperidol Doses IM

• The doses of haloperidol administered intramuscularly (IM) in various studies were:
  • 5 mg, 2 mg, and 1 mg in a study comparing the efficacy of haloperidol and chlorpromazine in acute psychotic patients 3
  • 7.5 mg in a study estimating the effects of IM haloperidol on the QT interval in volunteers with schizophrenia 4
  • 6.4 +/- 2.4 mg (range 2.5-10 mg) in a cost-minimization study comparing IM haloperidol and IM olanzapine for treating acute agitation 5
• The efficacy of these doses was evaluated in terms of their ability to control symptoms of acute psychosis, agitation, and disruptive behavior
• The results of these studies suggest that IM haloperidol is effective in controlling symptoms of acute psychosis and agitation, with response rates ranging from 83% to 100% 3, 6, 5
• However, the use of IM haloperidol has also been associated with adverse events, including extrapyramidal symptoms (EPS) and QT interval prolongation 3, 7, 4

Comparison with Other Antipsychotics

• IM haloperidol was compared with other antipsychotics, including chlorpromazine, olanzapine, and ziprasidone, in several studies
• The results of these studies suggest that IM haloperidol is at least as effective as these other antipsychotics in controlling symptoms of acute psychosis and agitation 3, 7, 5
• However, IM haloperidol was associated with a higher risk of adverse events, including EPS and QT interval prolongation, compared with some of these other antipsychotics 7, 4

Safety and Tolerability

• The safety and tolerability of IM haloperidol were evaluated in several studies
• The results of these studies suggest that IM haloperidol is generally safe and well-tolerated, with minimal adverse events reported 3, 6, 5
• However, the use of IM haloperidol has been associated with a risk of EPS and QT interval prolongation, which can be minimized with the use of antiparkinsonian medications and careful monitoring of patients 3, 7, 4